class_docstr: Consider implementing simple np sum method of label tags; Also add valid slices that have label mask
code: def __init__(
      self,
      tags=(
          DefaultLabelTag.FINAL.value,
          DefaultLabelTag.ORIGINAL.value,
      ),
  ):
      super().__init__("Compute Numpy Sum for Final/Original Labels")
      self.tags = tags
  
file_path: MONAILabel/monailabel/tasks/scoring/sum.py
imports: import logging
  import numpy
  import torch
  from monai.transforms import LoadImage
  from monailabel.interfaces.datastore import Datastore, DefaultLabelTag
  from monailabel.interfaces.tasks.scoring import ScoringMethod
label_desc: Use image node_id 1 to create a new Sum object from inherited base classes: ScoringMethod with example: obj = Sum(tags)